Meade 305 ƒ/10.4 LX200 • Royce 250 ƒ/19 Dall Kirkham • AstroTech 250 ƒ/8 RC • AstroTech 250 ƒ/4 "RFT" Newtonian • Meade 80 ƒ/6 ED APO • TEC 140 ƒ/7 APO • Orion 180 ƒ/15 Mak Cass ... Denkmeier II binoviewer - Nikon 8x60 binocular
Astronomical Files from Black Oak Observatory
Used acronyms: NEML=Naked Eye Magnitude Limit, SQM=Sky Quality Meter, TML=Telescope Magnitude Limit, CO=Central Obstruction, delta_m=difference in magnitudes between double star components, RoT=Rule of Thumb, pD_mm=proposed D_mm for resolving a binary (ident with earlier used pA=proposed Aperture), D_mm=Diameter (of scope) in mm, UCAC4=USNO CCD Astrograph Catalog 4th edition
Clear skies, Erik
Visual astronomer, main instruments:
Matthias Wirth 16" f/5 Takahashi FS-102 NSV on EM-10 Celestron 1983 C5
Zeiss, TeleVue and Celestron eyepieces
Nikon 18x70 IF-WP Zeiss Victory FL 7x42 Zeiss Victory FL 10x32
I want to do more then just look.
7x35 and 10x50 sears tower binocs, 3" f/10 edmunds reflector, 2.4" f/11.7 manon refractor, 6" f/8 jaegers refractor, 10" f/11 R30 Istar refractor, 3" f/15.8 sans&streiffe refractor, 3.1" f/15 selsi refractor(towa 339), 2.4" f/15 sears refractor, selsi 30x30mm spyglass, criterion 5-draw 25x45x75x spyglass(1957), 4.25" f/14.8 tasco 20te.http://cleardarksky.com/c/OmahaNEkey.html
Quote:If anyone cares to bring their big dobs or newts over to my place my 10" R30 Istar refractor is lookin' for an easy KO! Mike
Homemade 'scopes 8"f/7,6" f/5", 6"f/4, 4.25" Schiefspiegler,60mm Coronagraph,60mm H-alpha system, 4.25" White-light Solar Newtonian,solar spectroscope, 4" f/12, 4.5" f/16 & 6" f/12 Schupmann Medial refractors, 4" Celestar, 19 Stellafane awards 9 in optics Engineering = Taking what you have and making what you need.
Quote:Aimed at iota cas, increased the power on the 10" dob to 214x (never went above 175x before tonight)and the close companion came out of the primary's glare. At 250x, it was even better. Thanks for the optics lesson.
--------------------Clear Skies, PJ Refl.- 203/1420; Refr.- 110/616, 75/500; Bino.- 15X60, 10X50, 8X30 __________________________________________________
“I am the only person to ever ace a 1951 USAF resolution test. My 'to observe' list says 'done'. I do not use charts or atlases when I starhop; men do not use maps. One of my sketches won an SBIG deep sky imaging contest. I am the life of star parties I have never attended. I never say anything looks like a faint fuzzy - not even a faint fuzzy. Pilots aim green laser pointers at me. Don Pensack proofreads my CN forum posts.” - The Most Interesting Astronomer in the Universe
Quote:Some food for thought;http://neilenglish.net/the-mysterious-achromat/Regards,Neil.
Quote: Regarding Jim Barnett's comments - yes, the 10-inch will normally easily surpass any 4-inch. But I saw plenty of nights when the 16-inch I mentioned above was notably inferior to a 7-inch refractor, same night, same observing location. Pinpoint stars in the refractor, fuzzy blobs from thermal problems with the Newtonian.
Quote:... the practicable visual limit appears to be fixed around v.mag. 10: my experience puts it at around 9.5 with my 12" SCT...
Quote:I...To my eye, color saturation improves linearly with aperture...Jim
Quote:I dunno, bruce. To my eye, color saturation improves linearly with aperture. My 16" Dob always shows much more vivid star color than any of my smaller apertures, several of which you've sampled. Agree about the rest (best scope design for doubles being largely personal preference), but not about color intensity. Bigger scope of any design, more color than smaller scope of any design.